Identify and describe the functions of structures A, B, and C, and explain the procedure shown.

Part B points to the gland that secretes fluid into the ejaculatory duct.
Answer: The structure labeled B is the seminal vesicle.

2.5.2

Part A is the tube that transports sperm from the epididymis. This tube is shown as "cut and tied".

Answer: Part A (vas deferens) transports sperm from the epididymis to the ejaculatory duct.

2.5.3

Part C is the scrotum, which contains the testes.

The testes need a temperature slightly lower than the core body temperature for optimal sperm production (spermatogenesis).

On a hot day, the muscles in the scrotum relax, causing it to hang further away from the body. This increases the surface area exposed to the air, allowing for greater heat dissipation and cooling of the testes to maintain the ideal temperature for sperm viability.
Answer: Part C (the scrotum) moves away from the body on a very hot day to lower the temperature of the testes, as sperm production requires a temperature slightly below core body temperature.

2.5.4

The procedure involves cutting and tying part A (vas deferens), which is a vasectomy.

After a vasectomy, there may still be viable sperm present in the reproductive ducts (e.g., ejaculatory ducts, seminal vesicles) beyond the point of the cut. It takes time and several ejaculations for these residual sperm to be cleared from the system. If unprotected intercourse occurs too soon after the procedure, pregnancy can still occur. In rare cases, the cut ends of the vas deferens can also spontaneously reconnect.
Answer: This procedure (vasectomy) may fail to prevent pregnancy if sperm already present in the ducts beyond the cut are not fully cleared from the system before unprotected intercourse occurs, or if the cut ends of the vas deferens spontaneously reconnect.